Unexpectedly agile

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The lovely Orchelimum agile, most fleet-footed of katydids (Mason, OH).

I am always on the lookout for interesting orthopteran range expansions. Not only is it fun to hear new species calling in unfamiliar places, it also increases our knowledge of the spread of these animals and how this may be related to climate change and other human-influenced causes. I have written about the remarkable Orocharis saltator before, and now it’s time to note another traveler.

While driving down to Mississippi from Ithaca, NY, I kept track of what was singing in the vicinity of gas stations and rest areas where we stopped. Mostly it was the usual cast of characters – the trills of ground crickets, the short buzzes of short-winged meadow katydids, and indeed, the cheery calls of Orocharis as well. At one spot, a Dairy Queen in southern Ohio, I heard something different – a loud buzz preceded by a series of ticks. I recognized it as a greater meadow katydid in the genus Orchelimum. I don’t encounter species in this genus often so I was unsure of which species it could be at first. Tracking one individual in an ornamental yew in the parking lot, I spotted a large katydid with a pale face and a light green body. As I leaned in to get a better look, I accidentally jostled the bush and he bolted. I turned my attention to a second singer, again in a yew next to the Dairy Queen drive-in. This one stopped calling when I was a few feet from the bush, and standing in the middle of the drive-in, with cars maneuvering all around me, was clearly not an option. A third singer, calling from an ornamental juniper, was situated higher in the plant and was less shy. I caught him, but wrangling him into a vial was a difficult process as he was incredibly acrobatic, springing everywhere as soon as he was not restrained. Once I was able to get a good look at him, I recognized an old friend. This was Orchelimum agile, the Agile Meadow Katydid, an animal I had seen back in 2012 in central Florida. One of the most aptly named insects in my opinion, this is one of the most hyperactive species I have ever had the opportunity to encounter.

Range maps at Singing Insects of North America showed Ohio as being way far out of range for agile, but coincidentally I came across a very recent blog post that details their movements into southern Ohio. So turns out I was not the first one to see agile in Ohio, but this lithe creature was a significant record in any case.

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Orchelimum agile at Archbold Biological Station in FL in 2012.

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The Woodland Katydid

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Conocephalus nemoralis, the woodland meadow katydid (Starkville, MS). 

A few weeks ago I journeyed to Starkville, Mississippi, from Ithaca, New York with Jason Dombroskie of the CUIC. The purpose of our visit was, for Jason, to gather tortricid data from the Mississippi Entomological Museum at Mississippi State University; for me, it was a chance to chat about potential research projects with JoVonn Hill, an orthopterist based in Mississippi. Of course, being entomologists, we made time to collect along the way. While Jason set light traps and carefully pinned the moths harvested from said traps, I listened for unfamiliar songs and tracked down their creators. The trip yielded many orthopteran species I had only encountered once or twice before, as well as several species that I had never seen at all. One such species was Conocephalus nemoralis, the woodland meadow katydid. This was a species I was hoping to find, and find it I did; in fact I encountered them in almost every area we stopped to collect.

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Conocephalus nemoralis from Hoosier National Forest in Indiana. 

My first encounter with this pretty animal came in southern Indiana, in the Clover Lick Barrens of Hoosier National Forest. We arrived at dusk and hurried to set out light traps. Among the hundreds of singing insects, one call stood out. It sounded very much like the call of my shieldbacks that I had reared up earlier in the year (incidentally, the female and one male are still hanging in there), and I immediately thought that must be what was calling. Once I got around to tracking the song, I quickly found the singer and knew immediately what it was. There was no mistaking this little dark, wood-brown katydid and its short quiet buzzes. Over the course of the next hour I managed to capture two males and a female. The woodland meadow katydid is notable because it is intermediate in character between the closely related katydid genera Conocephalus and Orchelimum. The robust habitus and ovipositor shape are more typical of Orchelimum, but other characters place it as a Conocephalus.

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A female of Conocephalus nemoralis. Note the short, upcurved ovipositor that is more typical of Orchelimum katydids (Derby, IN). 

I was excited to have found nemoralis and suspected that I wouldn’t run across them again. Given the paucity of photos at BugGuide and other sources, I imagined that it wasn’t an especially common animal. However, this was certainly not the case, as I later picked up singing males at gas stations in Tennessee, university-owned properties in Mississippi, and even a rest stop in southern Pennsylvania on our way back to Ithaca. These varied localities had one thing in common – they were all edge habitats at the periphery of forests, which seems to be the preferred habitat of these little katydids. Most did not survive the trip back but one made it and is housed in my room, calling every day alongside native New York katydids.

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Habitat in Indiana where I found nemoralis – the Clover Lick Barrens. 

Sphagnum bogs, home of weird and wonderful creatures

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The Big Heath in Bass Harbor, MDI, Maine, is a good example of a northern sphagnum bog. Note the ericaceous shrubs in the foreground and the black spruce trees behind them.

Most of us have heard the term bog used colloquially to describe any wet, muddy area, but the true definition of a bog is a wetland that accumulates large deposits of dead plant material known as peat. Often this comes in the form of sphagnum, a genus of about 380 species of mosses that retain water especially well. True bogs are typically acidic and low in nutrients, and in many cases all water in the bog comes from precipitation. Most ordinary plants would die under these conditions, but of course there are quite a few that have adapted to these unfavorable circumstances, creating a distinct community of species that is nonexistent elsewhere. Unique plants, in turn, play host to unique insects.

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McLean Bogs in Tompkins county, NY, is an odd area containing a very small round sphagnum bog surrounded by glacial eskers.

I have had the fortune to be able to visit several sphagnum bogs in Maine and New York, and although each one has its own character, the same familiar plants and animals tend to greet me at every spot. The most obvious player is sphagnum moss, which forms a soft, spongy mat across every bog. When the mat is pressed, it gives up its water like a giant sponge, often evicting many small insects from their hideouts as they swim to safety. This is the primary way I find the dominant orthopteran inhabitant of eastern U.S. bogs, Neonemobius palustris. This tiny ground cricket lives exclusively in these habitats, and were it not for its song one would be hard pressed to detect its presence. Their tie to the sphagnum is quite obvious at the bog’s edge; there one can discern that where the sphagnum ends, the singing ends as well.

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A female nymph of the sphagnum ground cricket, Neonemobius palustris (McLean, NY).

Before I visited bogs to look for insects, I visited them to see a very special group of plants: the carnivorous plants. These unbelievable organisms that have to be seen to be believed only grow in places extremely deficient in nutrients, such as bogs or rock outcrops. They make up for the lack of soil nutrients by capturing and digesting insects and occasionally other small animals. Carnivory has apparently evolved independently in 9 different groups of plants, and thus there are a wide range of different prey capture strategies. The most well-known is the snap-trap of the venus’s fly trap (Dionaea muscipula), but that species is restricted to bogs in North and South Carolina (it is also widely cultivated in captivity). The types found in most eastern sphagnum bogs are several species of sundews and pitcher plants. Sundews (Drosera), which I surprisingly have no good photos of, consist of flattened leaves with hairs that bear drops of sticky sugary liquid on their tips. These attract insects, which get stuck and are eventually digested by the plant. Pitcher plants (Sarracenia), in contrast, are literally pitchers of liquid containing nectar bribes that lure insects to the edge, where they fall in and cannot escape. I am always guaranteed to see these fascinating little plants every time I enter a sphagnum bog.

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Northern pitcher plant, Sarracenia purpurea (McLean, NY).

Although carnivorous plants may seem to have turned the tables on insects, some insects have turned the tables again and evolved to take advantage of their captors. Wyeomyia smithii mosquitoes only breed in the pitchers of pitcher plants; moths of the genus Exyra feed exclusively on pitcher plants; Buckleria parvulus plume moth caterpillars feed on the sticky glue of sundews; Camponotus schmitzi ants are known as diving ants because of their habit of diving into the pitchers of pitcher plants and retrieving the plant’s food items. Unfortunately I have never had the good luck to encounter any of these tricky little animals at work.

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Lichnanthe vulpina, the bumblebee scarab. A member of the family Glaphyridae (once part of Scarabaeidae), this animal looks uncannily like a bumblebee in flight. Another name for this species is cranberry root grub because the larvae feed on the roots of cranberry plants (Kennebunk, ME).

Sphagnum moss and carnivorous plants are not the only plants present in bogs. Many specialized sedges and orchids live in bogs, as well as plants of the family Ericaceae (which includes such things as heaths, heathers, blueberries, and cranberries). Heaths are often host to some very strange insects, such as Lichnanthe vulpina, a bee-mimicking scarab beetle. Most trees cannot survive in bogs, but black spruce (Picea mariana) and tamarack (Larix laricina) often invade the open bogs, albeit in stunted form.

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Tamarack (Larix laricina), a common bog tree. This is a highly unusual tree that is a deciduous conifer – that is, it has all the characteristics of typical evergreens such as pines and spruces, except it loses its needles every fall! This photo was taken in October (Saco, ME).

If you have never experienced a bog before, do yourself a favor and visit one. Many bogs have boardwalks through them to facilitate public encounters, since walking directly on the sphagnum tramples and destroys the rare plants there. There are tons of awesome organisms in bogs, and I have only attempted to depict a few of the most interesting ones that I have seen here.

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The Saco Heath, a large bog open to the public with a long boardwalk. The white tufts are the seed heads of cotton grass (Eriophorum), a characteristic sedge in bogs.

Cicadas of the Cornell University Campus

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The face of a Linne’s Cicada (Neotibicen linnei). The large “grill”-like bump on the front of the face is the clypeus, which contains the muscles that act like a pump to power the cicada’s mouthparts.

The sizzling calls of cicadas are a familiar sound to anyone who has spent time outdoors on hot sunny days in late summer. Most cicadas sing from high in trees, making finding them a challenge. While they may all sound similar at first, their songs are all distinct and can be used to recognize species. I believe it is useful and fun to learn the calls of species that exist in your area. At the very least, it is a handy bit of trivia to have, and it’s also helpful in documenting biodiversity. With that in mind, here are the cicadas of Cornell University’s campus in Ithaca, New York. I have linked to recordings of each species from InsectSingers.com, a fantastic resource for cicadas.

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A male (left) and female (right) of the Linne’s Cicada. 

Neotibicen linnei, the Linne’s Cicada, is one of the two most common cicadas to be heard at Cornell. This species sounds a bit like a salt-and-pepper shaker to me. Its rattling buzz can be heard here. Individuals are nicely patterned in green and black, and have a prominent bend in the forewings that is a helpful guide to distinguish them from similar species. However this is not definitive, as some populations have less of a bend than others, and this should be used in conjunction with other traits to conclusively identify a specimen.

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Two females of the Lyric Cicada. Left is N. lyricen lyricen and right is N. lyricen engelhardti

Neotibicen lyricen, the Lyric Cicada, is the second of the two most common cicadas of Cornell’s campus. Its call is similar to the Linne’s but lacks the pulsations (hence the “lyric” moniker). It has been described as a syrupy buzz and can be heard here. I find that since these often drone on and on, they can become ‘white noise’ and fade from one’s notice easily. There is quite a bit of variation in the coloring of individuals. Around Ithaca there are two main color forms, known as N. lyricen lyricen and N. lyricen engelhardti. The former is patterned with greens, browns, reds, and tans while the latter is usually black with a very small amount of color on the pronotum, often in the shape of an anchor. These are not true subspecies and are better described as clinal variations. There are often intermediates in transitional zones such as Ithaca.

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A male Dog-day Cicada (Neotibicen canicularis).

Neotibicen canicularis, the Dog-day Cicada, is present on Cornell’s campus, but is not as abundant as the first two species mentioned. This is a more northern cicada, found in Canada and the northern tier of U.S. states. Its call is a high-pitched whine sounding like a buzz saw, and can be heard here. Dog-day cicadas look very similar to Linne’s cicadas but are quite a bit smaller.

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A comparison between a male Neotibicen linnei (left) and a male N. canicularis (right). Note the obvious size difference.

A few other species that I have not been able to document well here (or photograph) deserve brief mention:

I have heard Okanagana canadensis, the Canadian Cicada, numerous times around Cornell, but have been unable to find any. This is a very northern species on the southern edge of its range here. Males call from high in conifers. The call is an extended, cricket-like series of clicks (song).

Neotibicen tibicen, the Swamp Cicada, is a species that I think I have heard twice at Cornell, but both times were from quite a distance away. It is possible that these may have been Linne’s cicadas, as they sound rather similar (song). I will be listening for more this fall.

Finally, I must mention Neotibicen winnemanna, the Eastern scissor-grinder cicada. I heard this animal but once, at the edge of Cayuga lake in the early evening. However, there is no mistaking this cicada’s crazy call for anything else in the region. True to its name, it resembles the loud grating sound made by grinding scissors (song).

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A teneral (newly emerged) Linne’s cicada. At this stage they are very soft and vulnerable to predation. After several hours, the normal coloration sets in and the exoskeleton hardens up.

A katydid’s nightmare

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Something is clearly wrong with this katydid – note the discoloration and the head hanging by a thread.

One day in late July of this year, I was out on an early morning walk on the trails around Cornell’s campus. Heading down some stairs down to the Fall Creek gorge, I noticed a dead katydid on the ground and picked it up. I recognized it as a male Scudderia fasciata, the treetop bush katydid. This species lives high in conifers, and has dark striped wings to match its habitat. I usually find them either at lights or by accident, so I figured I’d keep this one as a specimen. I noticed that its head was hanging by a thread and that the entire head and thorax seemed to be empty. In stark contrast to this, the katydid’s abdomen was brown and bulging. Perhaps it was rotting? As I peered at it closer, a scene straight out of the movie Alien – four huge wriggling fly maggots burst forth from the katydid’s carcass! I am not one to be creeped out by insects, but this was such a shock that I dropped the whole mess! This was an especially creepy scene given that katydids are some of my favorite insects. After a moment I realized that this was a golden opportunity to see what fly species would be parasitizing bush katydids in upstate New York. I gathered up the fly larvae and dead katydid and placed them in a container with some soil.

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This is what keeps katydids up at night – a sarcophagid fly parasitoid of Scudderia fasciata, as yet unidentified.

In a few hours, the maggots had dug into the soil and pupated. I had no idea how long they would remain there, but less than two weeks later I looked at the container and four small flies were flitting around. They were sarcophagids, a group known as “flesh flies” that are known for feeding on dead bodies but which also contains species that parasitize other invertebrates. They are quite difficult to identify from photos alone, but I kept the specimens and hopefully I will be able to pin an ID on them some day.

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A healthy male Scudderia fasciata, found nearby several days later (Ithaca, NY).

In search of the green-legged grasshopper

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Melanoplus eurycercus, a member of the Melanoplus ‘viridipes group‘ (Cameron, NY)

The genus Melanoplus contains around 240 species of mostly dull-colored grasshoppers distributed over most of the nearctic region, with one species in Eurasia. It is the most species-rich genus of Orthoptera in North America, and not surprisingly it is also one of the most confusing. Most species can only reliably be told apart by the male genitalia, and many short-winged species in the southern U.S. are still undescribed. I have had experience with quite a few species of the genus, but one always stood out to me as one I really wanted to see. The Melanoplus ‘viridipes group’ includes around 12 very similar looking species collectively known as green-legged grasshoppers, which may be subspecies or geographic variations of one (more study is needed!). They have very short wings as adults, barely reaching the middle of the abdomen, and are vividly patterned in green and black. From what I could gather, they occurred in small colonies in open areas at forest edges. They do not appear in most field guides and are not well known.

While looking through specimens in the Cornell University Insect Collection (CUIC), I discovered that one species in the viridipes group, M. eurycercus, had apparently been recorded in and around Ithaca. In early July, my dad visited me in Ithaca and we decided to make a search for this animal. We first checked out a few sites within a few miles of Cornell’s campus, turning up quite a few orthopteran species, mostly nymphs, and even another Melanoplus that was new to me – M. confusus. While this was certainly exciting, I knew that my real quarry was still out there. The next day we visited an area about 1.5 hours away from Cornell that Jason Dombroskie of the CUIC had recommended I visit, Cameron State Forest.

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Melanoplus confusus, the pasture grasshopper. A widespread species found in sandy grasslands in late spring and early summer (Ithaca, NY).

Not more than 10 minutes into the hike, I noticed a sluggish grasshopper slowly moving across the path and quickly grabbed it. Excitement – it was a female of M. eurycercus! I bottled her and started moving ahead looking for more. The trail emerged out into a small forest clearing and then headed into the forest again. In the clearing I found 3 more females on the ground, some of them with heavy parasitic mite loads. All were quite easy to capture, just managing a couple of weak hops before settling in the grass. Once I thought I saw a male sitting in vegetation, but it disappeared before I could get a better look. A male would be the big prize, since they are much more strikingly patterned and also have the distinctive genitalia that would confirm their identity. After searching the clearing for a while, I decided to move on, hoping to find similar habitats.

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Females of M. eurycercus are more drab looking, but still share the characteristic pattern of the males. 

We spent the rest of the day walking the trail down to a small prairie area. Many interesting insects were present, including more Melanoplus confusus, but eurycercus had not shown itself since the original forest clearing. When we arrived back at the clearing while returning to the car, I decided to have another look to see if I could find a male. I spotted several more females before I saw what I was looking for – a gorgeous male eurycercus sitting on some low bramble leaves. I carefully moved towards him, but once I got within about two feet of him he spooked and shot off into the vegetation, never to be seen again. I knew now what I was up against, and began systematically combing the clearing for more. It took me about 20 minutes to find another, sitting at the edge of a thick fern tangle. I moved ever so slowly to try and intercept him before he noticed me. Of course he did notice me and made a high-powered leap into the ferns, but I was prepared. I slammed my cupped hands down onto the spot where it looked like he landed, and then slowly lifted my fingers, feeling for a struggling little presence. After a minute, it was looking like he wasn’t there. Suddenly I saw movement off to the right – I had misjudged my grab! I pounced on that spot, and sure enough I had him. He was lovely, looking just like the images I had seen at BugGuide. I find it extremely rewarding to come across something that you have never seen before and immediately recognize it due to having seen it in books or online. Of course now that I had put out all this effort to capture this one male, I caught another one within minutes that was just sitting on the trail and didn’t even try to hop off. This one was a bit more beat up, missing an antenna and hosting several mites.

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A heavily mite-infested female of Melanoplus eurycercus

So the entire adventure was a success. Males and females of my quarry, plus another species that I hadn’t even expected!

Georgia: Rearing the American Shieldback, Atlanticus americanus

DisclaimerThis has been my first experience keeping any members of this genus.

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Adult male American shieldback, Atlanticus americanus. Reared from nymph collected in Eatonton, GA.

A group of katydids that has consistently eluded me throughout the years is the shieldback katydids (subfamily Tettigoniinae). These tend to be large, bulky, dark-colored, and predacious species. For many years, the only one I had ever seen was the Roesel’s katydid, Roeseliana roeselii, an introduced European species found in the northeastern U.S. Almost all other U.S. shieldbacks live in the west, but there is a single widespread eastern genus, Atlanticus, plus a rarely seen southeastern specialty, Hubbelia marginifera (more here). I always wanted to see Atlanticus, as they present a very different image than more typical leafy-looking katydids. My wish was finally fulfilled in August 2014 when I ran across a single old male of Atlanticus testaceus in Delaware. However, I was not able to enjoy his presence long, as he died within a few days. This March, while in Georgia, I was thrilled to find that our campground was brimming with tiny shieldback nymphs, only a few millimeters each! They were abundant in the leaf litter of the forest surrounding Lake Sinclair. I captured as many as I could, but since I had limited space, I was forced to cram them all into a single large container. I knew that these could cannibalize, but hoped that at least some of them would make it back alive.

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Part of the original group of tiny shieldback nymphs. 

My fears were confirmed when I arrived back in Ithaca and sorted out the catch. Out of about 15 originally, only 6 had survived, and those individuals were fat on the meat of their brethren. I immediately separated them out into their own containers to prevent any more cannibalism. They seemed to adjust well to their new quarters and fed avidly on carrots and fish flakes, my standard orthopteran diet.

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One of the baby shieldbacks. 

I learned quickly that the shieldbacks were experts at molting in cramped conditions, unlike most katydids. They molted fine in their original small containers all the way up to their final nymphal instars. By this point, I had discerned an ovipositor on only one individual, meaning that I had 5 male nymphs and 1 female nymph. They were large enough that I began to supplement their diets with live prey (mostly small leafhoppers and moths caught locally), which they actively hunted down and ate. Once each shieldback started showing signs of getting ready to molt, I transferred them to a large container with a standing piece of corkbark for the imaginal molt. This worked perfectly, and although one of the male nymphs died unexpectedly from unknown reasons, all the rest became adults over the course of about a month.

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The largest male nymph, shortly before becoming an adult. 

When the first male nymph became an adult, I was able to key him out to Atlanticus americanus using a paper by Rehn and Hebard (1916). As adults, they became much more aggressive and predatory. Touching their antennae with forceps caused them to leap forward and start biting whatever was in front of them. On several occasions that turned out to be my finger, and I learned that they have powerful bites indeed. Unlike many other predatory animals such as spiders or assassin bugs, shieldbacks have no venom to quickly kill their prey. Instead, they rely on strong, fast bites to incapacitate their quarries. It was interesting to watch their strategies on various insect species. With smaller, weaker animals such as leafhoppers or caterpillars, they would simply grab the insect and start eating. With larger, more active prey, they would grab and attempt to start eating, but as soon as the prey started kicking and struggling to escape, the shieldbacks would systematically move up the body of the prey, biting at intervals until the insect stopped moving. Only then would the predator continue its meal.

In contrast to their dietary habits, I found their songs to be very peaceful and gentle. Two of the males have recently begun to sing. Their call is a series of soft, brief buzzes, repeated about a dozen times. They usually start singing at dusk and continue into the night. Fascinating that such a fierce predator would have such a tranquil voice.

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The single adult female shieldback. 

Reference:

Rehn, J. A., & Hebard, M. (1916). Studies in American Tettigoniidae (Orthoptera). VII. A Revision of the Species of the Genus Atlanticus (Decticinae). Transactions of the American Entomological Society (1890-), 42(1), 33-99.

 

Addendum: I originally wrote this post a few weeks ago and for some reason never got around to actually putting it up on the blog until now. All of my 5 shieldbacks are still alive and well, and the 4 males sing every night. Each tends to spur the others to sing, so that their buzzing becomes blended, and the chorus continues for well over the time span of a single male’s song. I can only imagine what it sounds like right now in their native home of Eatonton, Georgia.